Polycarbonate-polyorganosiloxane copolymer, polycarbonate resin composition including same, and molded product thereof

A polycarbonate-based resin composition, comprising:

• polycarbonate-polyorganosiloxane copolymers (A), each comprising polycarbonate blocks (A-1) each formed of a repeating unit represented by the following general formula (I);
• and
• polyorganosiloxane blocks (A-2) each containing a repeating unit represented by the following general formula (II), wherein the polycarbonate-polyorganosiloxane copolymers satisfy the following expression (F1a):
• 40≤wM1 (F1a);
• wherein wM1 represents an average content (mass %) of the polyorganosiloxane blocks (A-2) in a first fraction of the polycarbonate-polyorganosiloxane copolymers, each copolymer of the first fraction having a molecular weight calculated by gel permeation chromatography of from 56,000 or more to 200,000 or less, the first fraction is obtained through separation of the polycarbonate-polyorganosiloxane copolymers by gel permeation chromatography
• an aromatic polycarbonate-based resin (B) except the polycarbonate-polyorganosiloxane copolymers (A);
• and
• a styrene-based resin (C),
• wherein the styrene-based resin (C) is blended with respect to 100 parts by mass of a total of the polycarbonate-polyorganosiloxane copolymers (A) and the aromatic polycarbonate-based resin (B), and
• wherein a ratio of the polycarbonate-polyorganosiloxane copolymers (A) and the aromatic polycarbonate-based resin (B) in 100 mass % of a total amount of the polycarbonate-polyorganosiloxane copolymers (A) and the aromatic polycarbonate-based resin (B), and the styrene-based resin (C) is from 50 mass % or more to 99 mass % or less:
• wherein R1 and R2 each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, X represents a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, a fluorenediyl group, an arylalkylene group having 7 to 15 carbon atoms, an arylalkylidene group having 7 to 15 carbon atoms, —S—, —SO—, —SO2—, —O—, or —CO—, R3 and R4 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and “a” and “b” each independently represent an integer of from 0 to 4;
• wherein the viscosity-average molecular weight (Mv) of a polycarbonate-based resin formed of the polycarbonate-polyorganosiloxane copolymers (A) and the aromatic polycarbonate-based resin (B) is 9,000 or more and 23,000 or less and the content of the polyorganosiloxane blocks (A-2) in the polycarbonate-polyorganosiloxane copolymers (A) is 30 mass % or more and 70 mass % or less,
• wherein the polyorganosiloxane blocks (A-2) have an average chain length of from 55 or more to 120 or less;
• and
• wherein the composition does not comprise a rubber-modified styrene-based resin.